id: String value, mob model's ID. You can find it in $minecraft_root$\config\deepmobevolution\DataModels.json

modifier: Double value, the base output multiplier of this type model. It will output less life essence than normal model if this value is less than 1.0.

If certain model isn't defined here, its base output multiplier is 1.0 by default.

Make Ender Dragon model output 3x life essence

{
  "id": "dragon",
  "modifier": 3.0
}